Power operated hand held tool



June 28, 1960 HR. Flscnn ETAL Y POWER OPERATED-HAND HELD TOOL Filed June 16,1954

3 Sheets-Sheet iluvgu pnsr ATTORNEY June 28, 1960 H. R. FISCHER ETAL 2,942,507

POWER OPERATED HAND HELD TOOL 3 Sheets-Sheet 2 Filed June 16, 1954 QQ T m June 28, 1960 H. R. FISCHER ETAL 2,942,507

POWER OPERATED HAND HELD TOOL Filed June 16. 1954 s Sheets-Sheet 3 TJEIE: Z2

- INVENTORS:

Almeo E F 562? WYIIPCAZ A 01644:?

: ATTORNEY United S ates Patent POWER OPERATED HAND HELD TOOL Howard R. Fischer and Marcel P. DHaem, Utica, N.Y., assignors to Chicago Pneumatic Tool Company, New York, N.Y., a corporation of New Jersey Filed June 16, 1954, Ser. No. 437,257

9 Claims. (Cl. 8115) This invention relates to a power operated hand-held tool for use in metal working operations, more particularly for use in metal crimping or bending operations.

In certain types of wire joining operations, such as where a sleeve is to be crimped over a spliced wire, the need has developed for a small portable compressing tool which is power operated, for example, as by compressed air. Tools for such purpose have been designed and used and with varying degrees of success and/ or satisfaction. The present invention represents an improvement in tools of such type, and briefly includes such features as a maximum pressure indicator whereby the tool operator can observe whether the maximum pressure is being developed, a flexible connection between the tool piston and wedge to eliminate binding which may be caused by misalignment of operative parts, a simplified throttle valve control arrangement, means for conveniently adjusting the tool jaw opening to reduce hazard to the operator, a simplified means for holding the cylin der head of the tool in assembledposition, and very light overall weight.

The main object of this invention is to provide a tool for use in-metal-Working operations such as crimping and bending which is of light weight, is easy to operate, is rugged in use, and is of improved manufacture.

A further object is to provide a hand-held power operated crimping tool which includes means for observing whether the maximum pressure is being developed.

Another object is to provide a hand-held power operated crimping tool which includes means to eliminate binding of certain operative parts'of the tool.

Still another object is to provide a hand-held power operated crimping tool having a simplified throttle valve control arrangement.

Another object is to providea hand-held power operated crimping tool having means for conveniently adjusting tool jaw opening. a

A further object is to provide a hand-held power operated crimping tool having a simplified means for holding the cylinder head of the tool in assembled position.

These and further objects and features of the invention will become more apparent from an understanding of the following description when considered with the related drawings in which:

Fig. 1 is a side elevation view of a tool embodying the principles of the invention; 7

Fig. 2 is a front end view of the tool of Fig. 1;

Fig. 3 is a top view of the tool of Fig. 1;

. Fig.4 is a longitudinal section'view as seen from line -4-4inFig.3;

Fig. ,4Ais a section view of a throttle valve used in the tool of Fig. 1, as seen from line 4A-4A of Fig. '4;

Fig; 5 is a sectional view as seen from line 5-5 in Fig. 4; 1 l

Fig. 6 is a'sectional view as seen from line 6-6 in Fi .f4;...l i1

ice

Fig. 7 is a sectional view as seen from line 77 in Fig. 4;

Fig. 8 is a sectional view as seen from line 8-8 in Fig. 9 is a fragmentary sectional view illustrating a power range indicator of the tool as seen from line 9-9 in Fig. 8; and

Fig. 10 is a perspective view of a guard piece of the tool.

Figs. 1-3 inclusive are drawn to a smaller scale than the other figures.

Referring now to the drawings, numeral 21 indicates a cylinder which forms the main body of the tool, and which is preferably made from a light weight metal, such as aluminum. The exterior surface of the cylinder is of smooth finish, and has a plurality of longitudinal grooves 22 to provide for a firm grip when the tool is being held by the operator. Cylinder 21 is arranged to provide a jaw maintaining portion 23 and a piston portion 24 having a piston chamber 25 which is open at the rear end to receive a cylinder head adapter 26. A cylinder head adapter ring 27, which is made in two parts, is fitted in a groove 28 formed on the periphery of piston chamber 25, and extends into a recess 29 which extend about the edge of the cylinder head adapter 26,

as best seen in Fig. 4. The cylinder head adapter has a recess 31 on the inner front side, and extending from the bottom of the recess is a hole 32 which opens into the rear side of the adapter 26.

Abutting the rear edge of the piston portion 24, and

in contact with the adapter 26, is a cylinder head 33.

The latter is positionally mantained by means of four' screws 34, which extend through the cylinder head, and.

threadably engage the adapter. A gasket 36 is arranged. as shown to provide a fluid tight joint between the cylinder head 33 and the piston chamber 25. It will beseen. that by tightening the screws 34, the cylinder head is drawn in tight engagement with the adapter 26 and theend of the cylinder portion 24, since the adapteris restrained against rearward movement by the adapter ring? tegrally' arranged fins 42 (Fig. 4A) which engage the.

inner periphery of bushing 38. .At each. end of the throttle valve 41 is threadably ailixed a throttle valve ring cap 43 each of which maintains a sealing'ring 44 in a groove 46, formed adjacent a circular portion 47, the latter of which has a diameter slightly less'thari that of the bore of bushing 38. It will be seen that the rings 44 will seal the ends of the bushing 38 in each extreme position of the throttle valve 41. Threadablj aflixed Within the upper end of the bore 37, is a throttle valve cap 48, which is hollow to accommodate the upper throttlevalve ring cap 43. Opening into the bore'37, and in the region of the upper ring cap 43, is a passageway 49 which extends from a threaded bore 51 disposed in alignment with the axis of piston chamber 25.- The v threaded bore 51is adapted to receive a hosefittin'g (not shown), which forms part of a live air hose for delivery of pressure fluid to the tool. Pivotallyarrang'ed in a recess 52 formed'inthe cylinder head 33, isa'throftle valve lever orbell crank 53 which has an arm 54 arranged to engage the end of the lower throttle valve ring cap 43, and a depending 50 hav'ing a lost motiii hole 55 through which freely extends the rear end of .a throttle rod 56.

It will be seen that with the throttle valve 41 in the position shown in Fig. 4, live air in the upper part of bore 37 will be prevented from flowing into the bushing 38; however, when the throttle valve is moved upwardly by action of throttle lever 53, live air will be admitted to the piston chamber 25, by flowing about the unseated throttle valve into bushing 38, out through hole 39, then through hole 32 in adapter 26, and recess 31. Likewise, live air in piston chamber 25 will be released to atmosphere when the throttle valve is in the position shown in Fig. 4, via recess 31, holes 32 and 39, and about the lower end of throttle valve 41, and recess 52. Note that the lower circular portion 47 on throttle valve 41 will enter the bore of throttle valve bushing 38 at the same time the upper circular portion 47 is displaced therefrom, thus preventing escape of live air'along the lower end of the throttle valve 41.

Slidably arranged within the piston chamber 25 is a piston 57 to which is affixed a piston rod fork 58 by nut means 59, the latter of which enters into recess 41 of the adapter 26, when the piston is at the rear end of the piston chamber 25. A piston ring 61 is maintained in a groove 62 formed about the periphery of the piston 57, to provide a fluid sealing arrangement, for reasons which will be apparent. Pivotally affixed to the piston rod fork 58 by pin means 63, and enclosed within the jaw maintaining portion 23, is a wedge 64. On each side of the piston rod fork 58, and fixedly secured to the piston 57, is a return spring guide 66, as best seen in Fig. 5. Surrounding each spring guide 66 is a helical spring 67, one end of which abuts the forward end of piston 57, the other end of which abuts against an inner surface of the jaw maintaining portion 23 and a surface of a stationary jaw element 68. On the forward, or working stroke of the piston 57, the springs 67 are compressed and the energy thus stored therein will return the piston to the rear of the piston chamber 25, when pressure fluid is released from said piston chamber.

The stationary jaw element 68 is held in position within the tool portion 23, by means of roller shaft 69, and jaw shaft 71. Roller shaft 69 extends through the stationary jaw 68 and the jaw maintaining portion 23, and the ends thereof are grooved to receive split rings 72 (Fig. 6) which fix the shaft in position. The jaw shaft 71, as best seen in Fig. 5, is positioned within stationary jaw 68 and is recessed at each end to receive a shaft end piece 73 held in the jaw maintaining portion 23, each shaft end piece 73 being held in position by means of screws 74. The roller shaft 69 supports a roller 76 arranged upon needle bearings 77, while forwardly of, and parallel with, shaft 69 is another roller shaft 78, which is supported at each end in stationary jaw element 68. Roller shaft 78 supports a roller 79 arranged upon needle bearings 81. It is to be noted that rollers 76 and 79 are arranged so that each serves as a support for the lower surface of the wedge 64, said lower surface being generally of flat shape, and being parallel to the axis of piston chamber 25.

A moving jaw element 82 is supported on the jaw shaft 71 within the jaw maintaining portion 23. The jaw element 82 has an arm 83 extending rearwardly, which is bifurcated in its end for reception of a roller 84 supported upon a shaft 86, while a plurality of needle bearings 87 are arranged between the shaft and the roller. The roller 84 engages the upper surface of the wedge 64, said upper surface having two camming surfaces 88 and 89; camming surface 88 is at the forward end of the wedge and is arranged at an angle of 45 to. the bottom flat surface of the wedge, while camming surface-4'89, which joins with camming surface 88 is of generally arcuate shape laid out to provide whatever rate of jaw movement, or mechanical. advantage, is desired. As will beapp ecia e t he roller ii-passing. r m camm face 88 (relatively speaking) to camming surface 89, causes the end of the moving jaw element 82 to move more slowly and with greater pressure due to an increased mechanical advantage. Toward the end of the camming surface 89, a flat, or straight line surface 90, is provided whereby little movement of the jaw is to be had, however, the effective pressure produced is maximum. The forward end of the moving jaw element 82 is adapted to receive one part 91 of a removable pressing die, another part 92 of the pressing die being aflixed in opposition thereto in the end of stationary jaw element 68, as shown. Screw means 93, as best seen in Fig. 7, are arranged to maintain the parts 91, 92 of the pressing die in position upon the respective jaw elements.

From the foregoing it will be seen that as the piston 57 moves forwardly in piston chamber 25, the wedge cam surfaces 88, 89 cause the moving jaw arm 83 to swing in an upward direction, thus moving the die part 91 toward die part 92; conversely when the piston moves rearwardly in the piston chamber, the arm 83, following camming surfaces 88, 89 will swing on a downward direction causing die part 91 to move away from die part 92. For purpose of urging the jaw arm 83 downwardly, a return spring 94 (Figs. 4 and 6) is compressively arranged between an abutment 96 formed in the stationary jaw element 68, and a radial shoulder 97 formed on a pin member 98, the latter of which has a reduced diameter projection or stub pin 99 which abuts an extension or ear 101 formed on the moving jaw element 82. Spring 94 is retained and centralized with respect to the abutment 96 by means of a forwardly extending lug 96a integral with said abutment. An adjusting screw 102 is positioned in a threaded opening in the stationary jaw-element 68, whereby the jaw extension 101 will engage the end of said screw 102, to limit the extent of jaw movement in the opening direction, or in other words, to limit the degree of movement of die part 91 away from die part 92. By such adjusting means, the tool jaw gap may be regulated to open only as wide as necessary to engage a work piece, thus reducing hazard to the operator, such as would be present if the jaw opening was wider than necessary to engage the work.

Pivotally arranged in a lower part of the jaw maintaining portion 23 by means of a pin member 100, is a throttle lever 103, the major portion of which extends rearwardly, and which in non-operative position, is parallel to the 'axis of the tool. The throttle lever .103 has an extension 104 which is adapted to slidingly receive the throttle rod 56, and abut the underside of a head portion 106 formed upon the throttle rod. The head portion 106 is slotted whereby the throttle rod may be rotated for adjustment, which is effected by drawing up a nut 107 threadably aflixed to the rear end of throttle rod, said nut being held against rotation by virtue of the fact that the walls of recess 52 engage the fiat sides thereof. A guard piece 108 (Fig. 10) positioned forwardly of the throttle rod head 106 is held in place by a pair of cars 108a at one end thereof engaging the pin 100, and by means of a flange 108b at the opposite end thereof slipped over the adjusting screw 102, as best seen in Figs. 4 and 6. An enlarged hole 108s in the guard piece 108 provides access for a screw driver to the slotted head portion 106 for purposes of adjusting the throttle rod relative to the nut 107.

A maximum pressure indicator is arranged on the tool and comprises a pin member 109 slidably supported in a 'bore 111, formed in the jaw maintaining portion 23. As best seen in Fig. 9 the rear end of pin member 109 enters into the piston chamber 25 for engagement with the forward surface of piston 57, while the forward end enters into a recess 112, formed in the side of the jaw maintaining portion 23. The forward end of pin member 109, has a reduced diameter portion 110, which is slidably supported in a bore formed in the jaw maintaining portion 23; said reduced diameter portion 110, serves to prevent the accidental pinching of an operators finger should it be placed in the recess 112 during tool operation. Two guide lines 113, 114 are scratched within recess 112 whereby the extent of travel of pin 109, by action of piston 57, can be observed as the shoulder 109a defined by the reduced portion 110 moves relative to the guide lines 113 and 114. The portion 90 of the camming surface 89, corresponds to movement of pin 109 between lines 114, 113, hence the compressive force developed thereon, will be substantially uniform and at a maximum. To obtain a maximum pressure reading, the tool operator need only push the pin 109 rearwardly prior to tool operation; as the piston 57 moves forward in piston chamber 25 on a power stroke, it will contact the pin 109 and push it forwardly. Guide line 113 may be established to show when piston 57 has reached the end of its stroke; development of maximum pressure under given live air pressure, will occur when the shoulder 109a of pin 109 is between guide lines 114 and 113. It will be understood that the maximum compressive power of any tool according to the invention, will depend upon variables such as the shape, or slope, of camming surface 89, the area of the piston 57, and the live air pressure acting within piston chamber 25. Furthermore, if the die parts 91, 92 are too thick, the movable jaw 82 will not be able to swing sufficiently so that the roller 84 is contacting the rearward end of camming surface 89, Where maximum pressure is developed. If upon taking a reading on the maximum pressure indicator, the operator observes that the shoulder 109a of pin 109 is not between lines 114 and 113, the operator will know that the movable jaw 82 has not been rotated the proper amount required for the attainment of maximum pressure; he can then check the die parts 91, 92 to see if they are of proper size (thickness), and/or he can check the live air pressure to see if it is of proper amount.

- The maximum pressure indicator is thus seen to pro vide a simple and effective means to inform the tool operator as to when maximum pressure is being applied in crimping'operations. By way of example, a tool having proportions similar to that illustrated in the draw ings, will develop a maximum compressive force of 3700 lbs., when operating on a 90 p.s.i.' air pressure; thus when the end ofpin 109 moves to a position somewhere betweenlines 114 and 113 during tool operation, the tool operator knows that the maximum compressive force of 3700 lbs. is being developed. In such tool, the jaw movement associated with movement of pin 109 between lines 114 and 113, is in the order of one ten-thousandth inch.

The operation of the tool should be readily apparent. Once the tool has been connected to a source of live air pressure, the operator need only squeeze the throttle lever 103, with a finger of the hand in which the tool is being held, to cause air to enter piston chamber 25, and send the piston 57 forwardly upon a power stroke. Ac-

While the invention has been described as embodied ina crimping tool, it will be readily apparent that the features of the invention may be easily applied to other types of hand-held power operated metal working tools.

Accordingly, the invention is not to be limited to the tool of the foregoing disclosure, but rather is to be limited by the scope of the appended claims.

What is claimed is:

l. A power operated hand-held tool comprising in combination a, cylinder means including a jaw maintaining portion and a piston portion the latter of which has a piston chamber, a piston means slidably arranged within the piston chamber and having a wedge afiixed thereto which extends into the jaw maintaining portion, a sta-' tionary jaw element positioned in the jaw maintaining portion and having a work operating end, a moving jaw element pivotally arranged in the jaw maintaining portion and having an arm engageable with the wedge and, further having a work operating end movable into alignment with the work operating end of the stationary jaw element, said piston means adapted to move forwardly upon a compression stroke whereby the wedge will impart rotational movement to the moving jaw element for development of compressive force between said work operating ends, and an indicator means mounted upon the tool and adapted to indicate the maximum compres sive pressure being developed by movement of the piston means; wherein the indicating means comprises a recessin the ,outer face of the cylinder, visible reference marks in the wall of the recess, a rod slidable in the wall of the cylinder across the recess in parallel relation to the longitudinal axis of the piston, a shoulder in the rod movable with the latter relative to the reference marks, one end of the rod being projectible into the piston chamber into the path of forward movement of the piston on a compression stroke, whereby the piston is caused to progressively slide the rod across the recess as the piston moves forwardly on a compression stroke,.and the recess allowing manual access to the rod to so project it.

2. A power operated hand-held tool according to claim 1, wherein a throttle valve means is arranged at the rear end of the piston portion adapted for operation to admit live air to the piston chamber to drive the piston means forwardly on a compression stroke.

3.1A power operated hand-held tool according to claim 2, wherein a throttle lever is pivotally aflixed to the jaw maintaining portion, and a connection means extends from said throttle lever for connection with throttle control means arranged in the piston portion said throttle control means adapted for operation of said throttle valve means. 7

4., A pneumatic tool comprising a cylinder providing a piston chamber, a back head for said cylinder, a throttle valve for controlling the supply of live air to the piston tuation of the throttle lever 103 draws the throttle rod 5 6 forwardly and turns the bell cranke S3 clockwise (Fig. 4) to slide valve 41 to open position. The head end 106 ofthe throttle rod isnormally, as appears in Fig. 4, in close proximity to the guide piece 108. To

throttle rod, the hole 1080 is sufficiently large enough to freely receive the head end 106 of thethrottle rod as it is drawn forwardly by the throttle lever 103. A single power stroke is generally sufiicient for the usual crimping operation. Upon release of the throttle lever 103, the throttle valve 41 will move downwardly, by virtue of live air acting thereupon, thereby releasing air in piston chamber 25 to atmosphere, whereupon piston 57 will be moved rearwardly in the piston chamber, and the throttle lever 103 will be drawn back into nonchamber and mounted to reciprocate in a transverse bore in the backhead, a front head on the cylinder, a manipulative lever pivotally supported on the front head, a bell crank lever pivoted to the back head and engaging the throttle valve to move it in one direction, and an elonllow .f f unobstructed f d movement of the gated rod connecting the manipulative lever with the bell crank lever to provide a remote control for the throttle valve, the manipulative lever having a pivot axis transverse to the cylinder, said rod being arranged to reciprocate longitudinally of the cylinder, and the bell crank supporting the lever in the housing whereby the jaw end thereof may be pivoted to and from the fixed jaw, spring loaded means constantly urging the lever to pivot to open positionrelative to the fixed jaw, pneumatically powered piston cam means for engaging the bearing surface of the lever and causing the lever to pivot to closed position against the load of the spring means, and control means in the housing for controlling a flow of pneumatic fluid to drive the piston cam means; wherein the spring loaded means comprises an abutment in the housing having a forwardly extending lug, a coil spring sleeved over the lug at one end and limiting against the abutment, a pin inserted into the opposite end of the coil spring and having a radial shoulder abutting the adjacent end of the latter spring, an ear depending from the lever, and a stub pin projecting axially from the shoulder into abutment with the ear whereby the lever is pivotable under the load of the coil spring to open position, the ear of the lever being adapted to ride angularly over the stub pin as the lever pivots.

6. A power operated hand tool as in claim 5, wherein an adjustable stop is supported in the housing and is extendable into the path of movement of the ear of the lever to curb the extent of pivotable movement of the lever under the load of the coil spring.

7. A power operated hand tool including a housing and a fixed jaw defined by the forward end of the housing, a lever member having a complementary jaw at its forward end for engaging the fixed jaw and having a bearing surface at its opposite end, means pivotally sup porting the lever in the housing whereby the jaw end thereof may be pivoted to closed and open positions relative to the fixed jaw, spring loaded means constantly urging the lever to pivot to open position, a piston cylinder providing a piston chamber in the housing, and a cam piston pneumatically movable in the chamber to progressively engage the bearing surface of the lever and cause the latter toprogressively pivot its jaw end to closed position against the load of the spring means, and indicating means for visibly indicating the extent of the movement of the cam piston relative to the lever member; wherein the latter means comprises an outer recess formed in the wall of the housing, a first bore of small diameter extending forwardly from the recess in parallel relation to the axis of the cam piston, a second bore concentric with the first and of larger diameter extending from the recess to the pistonchamber, an elongated rod slidable in these bores including a forward reduced portion having a slide'fit in the small bore and including an enlarged rear portion having a slide fit in the enlarged bore, the rod being adapted by means of the recess to be manually moved to project a rear portion thereof into the piston chamber, visible reference marks formed in the wall of the recess along the path of movement of the rod, the projected portion of the rod being adapted to be moved by the cam piston forwardly out of the piston chamber upon a forward movement of the cam piston, and a shoulder in the rod defined by the reduced portion thereof adapted to be carried forwardly in the recess relative to the reference marks as the cam piston moves against the projected portion of the rod.

8. A pneumatic tool according to claim 4, the rod being confined at its ends within corresponding recess portions of the cylinder, a rear end of the rod having a slide connection with the bell crank, a retaining nut threaded on an end portion of the rod projecting from the bell crank, the retaining nut having flat sides engaging the adjacent walls of the related recess whereby the nut is restrained against rotation, the opposite end of the rod being slotted, and access of a screw driver to the slotted end of the rod for adjustment of the length of the rod relative to the nut being provided by an opening into the cylinder.

9. A power operated hand tool including a housing and a fixed jaw at the forward end of the housing; a lever member having a complementary jaw at its forward end for engagement with the fixed jaw and having a bearing surface at its opposite end; means pivotally supporting the lever in the housing whereby the jaw end thereof may be pivoted to and from the fixed jaw; spring loaded means constantly urging the lever to pivot to open position relative to the fixed jaw; a pneumatically powered cam piston for engaging the bearing surface of the lever on a compression forward stroke and causing the lever to pivot to closed position against the load of the spring means; and means for visibly indicating the extent of forward movement of the cam piston on a compression stroke, comprising a bore in the wall of the housing parallel to the longitudinal axis of the piston and having a rear end opening into the piston chamber, a recess in the outer side face of the housing intersecting said bore, visible reference marks in a wall of the recess, a rod slidably supported at its ends in the bore for movement of its intermediate portion across the recess in parallel relation to the longitudinal axis of the piston, and an abutment defining an indicator formed intermediately of the ends of the rod and movable in the recess with the latter relative to the reference marks, wherein one end of the rod is projectible through said rear end of the bore into the piston chamber into the path of forward movement of the piston, whereby the rod is caused to progressively slide across the recess as the piston moves forwardly, and the recess having a forward wall engageable by the abutment for limiting the extent of the forward movement of the rod across the recess.

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